1. NATURAL SUBSTANCE UNDER THE GROUND [uncountable] the thick dark liquid from under the ground from which petrol is produced ⇒ crude: a rise in the price of oil the importance of protecting our oil supplies an oil refinery (=factory where oil is made purer)

2. FUEL [uncountable] a smooth thick liquid that is used to make machines run easily or is burned to produce heat: Check the oil level in your car every week. The heating system runs on oil.

3. LIQUID FROM PLANTS [uncountable and countable] a smooth thick liquid made from plants or some animals, used especially in cooking or for making beauty products: cooking oilolive/vegetable/sunflower etc oil coconut oil shampoo Fish oils are supposed to help relieve arthritis. ⇒ castor oil, cod-liver oil, linseed oil

discover/find oilOil was discovered in Saudi Arabia in 1938.How does a company go about finding oil and getting it from the ground?hit/strike oil (=to find oil when you are digging for it)The engineers drilled down a few hundred metres until they hit oil.The Ohio Oil Company struck oil on May 3rd.drill for oilPlans to drill for oil off the New South Wales coast have recently been revived.produce oil (=to have natural areas of oil, and take it out of the ground)The US does not produce enough oil to meet its own needs.extract oil formal (=to take oil out of an area)the difficult process of extracting the oilcrude oil (=oil in its natural state)the price of crude oilrefined oil (=oil that has been treated by an industrial process)They had exported refined oil.offshore oil (=found under the sea, not far from the coast)The company has the technical capabilities to produce offshore oil.heavy/light oil2,000 barrels of heavy oil are produced a day.The oil corporation announced the discovery of another field of light oil.oil pricesThe increase in oil prices has prompted warnings of a global recession.the oil industryHe works in in the oil industry.an oil companyYPF was the state oil company in Argentina.an oil producer (=a country which produces oil)The Soviet Union is the world's largest oil producer.an oil refinery (=a place where oil is treated by an industrial process)an oil refinery in Perthoil productiona fall in US oil productionan oil spill (=situation in which oil comes out of a ship or other container into the sea)a terrible oil spill near the Shetland Islandsan oil crisis (=situation in which there is not enough oil, and the price of oil is very high)The world is facing an oil crisis.an oil rig (=structure on land or in the sea with equipment for getting oil out of the ground)an oil rig in the North Sea